Polymers 0.0 / 5 ? PhysicsMaterialsA2/A-levelOCR Created by: louderthanbombzzCreated on: 06-04-17 16:55 What are macromolecules? Long-chained molecules formed from single unit monomers with C=C double bonds in monomers. 1 of 16 What are condensation reactions in polymers? 2 monomers are joined, releasing water. 2 of 16 What is polymerisation? Joining monomers to make a polymer. 3 of 16 What is cross-linking? Adding physical linkages between chains to make rotation/unfolding harder. 4 of 16 What are covalent bonds known to be? Strong and directional, unlike weak London forces. 5 of 16 How are solids formed? Atoms and molecules lose kinetic energy. 6 of 16 What is vulcanisation? Natural rubber is heated with sulphur and cross-links form with the rubber polymer chains. 7 of 16 What material has linear polymer chain arrangement? Glucagon. 8 of 16 What material has branched, less compact, chain arrangement? Amylopectin. 9 of 16 What material has cross-linked structure? Vulcanised rubber. 10 of 16 What makes polymers flexible? Polymer chains can rotate around bonds, increasing elasticity. Arrangement of atoms can stop this. 11 of 16 In PTFE, tetrafluoroethene monomers, which atom is large relative to monomer size, stopping rotation? Fluorine 12 of 16 What are crystalline polymers? Polymers with regular structure of lined chains, with stronger Van der Waals forces, giving higher m/b points. 13 of 16 Polymers can also be amorphous, true or false? True 14 of 16 Polythene, 10*100mm, is semi-crystalline. Stretching plastically makes amorphous regions... Line up. 15 of 16 What are smart polymers? Stimuli responsive and can alter colour/transparency/conductivity/shape with stimuli, high performance. 16 of 16
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